I'd go with the Corsair as well, I looked pretty hard at that PSU recently when trying to pick my new one out...

FYI: Don't just compare voltage ratings, take everything into consideration, like how many rails it may have.
Another good thing to do is google for some reviews when comparing two or more components, as I can see some have already provided links to for you.

The corsair only has one actual rail - my 620 has 3 virtual rails as due to the ATX specifications it says you cannot have more than so much [20 amps?] per cable [rail] so the psu has 3 actual cables connected to the 12v output from the PSU's PCB
So the Corsairs don't have 3 actual rails - just one 54amp rail with 3 cables coming from it

The HX-620 will power almost any system possible - as i said earlier - my systems is no slouch and the fan dosent even spin up so the actual load is fairly low with my system..... even during games the psu dosent spin up the fan....

You may also want to look at the Zalman PSU's. If you don't care for modular cabling, then you may want to look at OCZ's GameXStream line, since the Zalman is almost identical, only with heatpipe cooling, and as I mentioned, modular cabling.